Longmoor Lane was closed while police helped deal with the incident. It is understood officers will now examine CCTV and arrests could be made.

A Merseyside Police spokesman said: "At the moment our priority is dealing with the road traffic accident which has left a young man in a critical condition."

Mr Cooke said he was "proud" of his officers but "disgusted by the pathetic louts who did this."

He later added: "It's important that the vast majority of Merseyside's law abiding public who support the police understand the challenges my officers face when they are helping others and doing their job."